Operator s receiving-telephone



(No Model.)

E. BERLINER.

OPERATORS RECEIVING TELEPHONE.

Patented Aug. 22 1882.

N2 PETERS. Mu-mhom m, Wahinginn, no.

LIA

UNITED STATES PATENT OFFICE.

EMILE BERLINER, OF BOSTON, MASSACHUSETTS.

OPERATORS RECEIVING-TELEPHONE.

SPECIFICATION forming part of Letters Patent No. 262,921, dated August 22, 1882.

Application filed April 15, 1882. (No model.)

To all whom it may concern:

Be it known that I, EMILE BERLINER, of Boston, in the county of Sufi'olk and State of Massachusetts, have i nven ted certain Improvements in Operators Receiving-Telephones, of which the following is a specification.

This invention relates to the class of telephones which are used by operators or others whose occupation requiresalong-continued listening to electrically-transmitted intelligence, particularly articulate sound, and refers more definitely to receiving-telephones which are strapped to the ear. Hitherto it has been found difficult to make a receiving-telephone which is strapped to the ear, and is light enough so as not to interfere with the comfort of the operator and at the same time be efficient in service long continued. The reason is that in the practical receiving-telephone a certain amount of magnetic strength is required to polarize an electro-magnet, and as this magnetism represents a certain weight in steel (or also a certain weight in insulated wire and iron Where an electro-magnet is substituted for a permanent magnet) it has been found that carrying this weight on ones head interferes with ones comfort and health. It has been tried to substitute steel springs for the ordinary bar-steel, and shape them so that they will exert pressure only to the sides of the head; but in such steel springs the magnetism is not permanent and rapidly loses its strength.

In my improvement 1 disconnect the magnet from the receiving-telephone, and make the former part of the stations fixtures near the operators car, so that the remaining parts of the telephoneviz., the sounding-chamber, electro-magnet, and diaphragm--which are strapped to that car are in its magnetic field. This is shown in the drawings, as follows:

In Figure 1 the telephoneAis strapped to the operators ear by the strings d d. The magnet B is screwed to the spring G by means of the screw and nut to b, and the said spring 0 to the station fixtures D. The spring 0 is provided with a slot through which the screw a passes, thus permitting the magnet B to be raised to dilferent heights, according to the usual position of each individual operator.

In Fig. 2 the parts of the telephone are more specifically shown. Here are the diaphragm K, electromagnet i, and sounding-chamber parts 0 and f. The core of the electro-magnet is fixed tothe iron plate j. g is another plate, forming a holder, and to this plate the string 01 is attached. A cushion of soft material, h, is. preferably glued to the back of the telephone, in order to prevent any noise in case the operator should strike with the telephone against the magnet B. As a further feature in this direction may be counted the spring G in Fig. 1, which permits the magnet to yield in case the operator should touch it.

It is evidentflom the above description that the requirements sought after in my invention are perfectly met-viz., a receiving-telephone of lightweight is strapped to the operators ear, and magnetism of unlimited strength is supplied without additional weight to the operators head or discomfort of any kind. Therefore I claim- 1. A receiving telephone consisting of a sounding-chamber, diaphragm, and inert electro-rnagnet, which is included in a telephonecircuit, and provided with straps adapted to secure the instrumen t to an operators ear, in combination with a detached magnet located, as

described, so that the telephone may be within the magnetic field of the magnet.

2. A receiving telephone consisting of a sounding-chamber, diaphragm, and inert electro-magnet, which is included in a telephonecircuit and pressed against an operators ear, in combination with adetached ma gnetlocated, as described, so that the telephone may be within the magnetic field of the magnet.

In testimony whereof I have signed my name to this speeification,in the presence of two subscribing witnesses, this 14th day of April, 1882.

EMILE BERIlINER.

Witnesses:

J. H. CHEEVER, GEO. WILLIS PIERCE. 

